Functional anatomy of the vagus system: How does the polyvagal theory comply?

Due to its pivotal role in autonomic networks and interoception, the vagus attracts continued interest from both basic scientists and therapists of various clinical disciplines. In particular, the widespread use of heart rate variability as an index of autonomic cardiac control and a proposed central role of the vagus in biopsychological concepts, e.g., the polyvagal theory, provide a good opportunity to recall basic features of vagal anatomy. In addition to the classical vagal brainstem nuclei, i.e., dorsal motor nucleus, nucleus ambiguus and nucleus tractus solitarii, the spinal trigeminal and paratrigeminal nuclei come into play as targets of vagal afferents. On the other hand, the nucleus of the solitary tract receives and integrates not only visceral but also somatic afferents.

Automated summary

Due to its important role in autonomic networks and interoception, the vagus nerve continues to attract interest from both basic scientists and therapists. In addition to the classical vagal brainstem nuclei, the spinal trigeminal and paratrigeminal nuclei also play a role in vagal innervation. Furthermore, the nucleus of the solitary tract integrates not only visceral but also somatic sensory inputs.